The invention relates to a junction field effect transistor having a substantially quadratic relationship between the channel current I.sub.DS and the gate voltage V.sub.GS over at least a part of the I.sub.DS -V.sub.GS characteristic, comprising a semiconductor body having a semiconductor substrate of a first conductivity type which is provided with a surface region of the second, opposite conductivity type which adjoins the surface of the body and which comprises a source zone and a drain zone and an intermediately-located channel region of the second conductivity type, and which is provided with at least one surface-adjoining gate region which forms a rectifying junction with the channel region.
Circuit elements having a quadratic characteristic are generally desired because they give little or no nonlinear distortion in, for example, mixing devices and high frequency amplifier stages. Since no intermodulation occurs in a circuit element with a truly quadratic characteristic, such circuit elements can also be used very readily in tuning units (inter alia FM tuners).
The use of field effect transistors in this kind of circuits is generally known. It has been found, however, that they approach the quadratic characteristic only over a small part of the gate voltage range.